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Liquid‐Crystalline Polymethacrylates by Atom‐Transfer Radical Polymerization at Ambient Temperature
Author(s) -
Li MinHui,
Keller Patrick,
Grelet Eric,
Auroy Philippe
Publication year - 2002
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20020301)203:4<619::aid-macp619>3.0.co;2-s
Subject(s) - thermotropic crystal , atom transfer radical polymerization , polymer chemistry , differential scanning calorimetry , polymerization , polymer , radical polymerization , side chain , chemistry , methacrylate , molar mass distribution , materials science , organic chemistry , liquid crystalline , thermodynamics , physics
Side‐on and side‐end liquid‐crystalline (LC) polymethacrylates were synthesized by atom‐transfer radical polymerization at 20°C using monofunctional and difunctional initiators. The polymers have narrow molecular‐weight distributions ( M̄ w / M̄ n = 1.15–1.45). The polymerization kinetics were determined for a side‐on LC methacrylate, and appear to be first‐order, whatever the initiator used. However, the measured molecular weight is much larger than expected, probably because the initiation step is slow. The thermotropic properties of the LC polymers were studied by thermal optical polarizing microscopy, differential scanning calorimetry, and X‐ray diffraction. For a side‐end LC polymethacrylate, two LC phases were detected although only one has been reported in the literature. The phase sequence was shown to be Cr–SmA–N–Iso.